1 /* cat -- concatenate files and print on the standard output.
2 Copyright (C) 88, 90, 91, 1995-2008 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Differences from the Unix cat:
18 * Always unbuffered, -u is ignored.
19 * Usually much faster than other versions of cat, the difference
20 is especially apparent when using the -v option.
22 By tege@sics.se, Torbjorn Granlund, advised by rms, Richard Stallman. */
28 #include <sys/types.h>
34 # include <sys/ioctl.h>
39 #include "full-write.h"
41 #include "safe-read.h"
43 /* The official name of this program (e.g., no `g' prefix). */
44 #define PROGRAM_NAME "cat"
47 proper_name_utf8 ("Torbjorn Granlund", "Torbj\303\266rn Granlund"), \
48 proper_name ("Richard M. Stallman")
50 /* Undefine, to avoid warning about redefinition on some systems. */
52 #define max(h,i) ((h) > (i) ? (h) : (i))
54 /* Name of input file. May be "-". */
55 static char const *infile;
57 /* Descriptor on which input file is open. */
58 static int input_desc;
60 /* Buffer for line numbers.
61 An 11 digit counter may overflow within an hour on a P2/466,
62 an 18 digit counter needs about 1000y */
63 #define LINE_COUNTER_BUF_LEN 20
64 static char line_buf[LINE_COUNTER_BUF_LEN] =
66 ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
67 ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '0',
71 /* Position in `line_buf' where printing starts. This will not change
72 unless the number of lines is larger than 999999. */
73 static char *line_num_print = line_buf + LINE_COUNTER_BUF_LEN - 8;
75 /* Position of the first digit in `line_buf'. */
76 static char *line_num_start = line_buf + LINE_COUNTER_BUF_LEN - 3;
78 /* Position of the last digit in `line_buf'. */
79 static char *line_num_end = line_buf + LINE_COUNTER_BUF_LEN - 3;
81 /* Preserves the `cat' function's local `newlines' between invocations. */
82 static int newlines2 = 0;
87 if (status != EXIT_SUCCESS)
88 fprintf (stderr, _("Try `%s --help' for more information.\n"),
93 Usage: %s [OPTION] [FILE]...\n\
97 Concatenate FILE(s), or standard input, to standard output.\n\
99 -A, --show-all equivalent to -vET\n\
100 -b, --number-nonblank number nonempty output lines\n\
101 -e equivalent to -vE\n\
102 -E, --show-ends display $ at end of each line\n\
103 -n, --number number all output lines\n\
104 -s, --squeeze-blank suppress repeated empty output lines\n\
107 -t equivalent to -vT\n\
108 -T, --show-tabs display TAB characters as ^I\n\
110 -v, --show-nonprinting use ^ and M- notation, except for LFD and TAB\n\
112 fputs (HELP_OPTION_DESCRIPTION, stdout);
113 fputs (VERSION_OPTION_DESCRIPTION, stdout);
116 With no FILE, or when FILE is -, read standard input.\n\
121 %s f - g Output f's contents, then standard input, then g's contents.\n\
122 %s Copy standard input to standard output.\n\
124 program_name, program_name);
125 emit_bug_reporting_address ();
130 /* Compute the next line number. */
135 char *endp = line_num_end;
142 while (endp >= line_num_start);
143 if (line_num_start > line_buf)
144 *--line_num_start = '1';
147 if (line_num_start < line_num_print)
151 /* Plain cat. Copies the file behind `input_desc' to STDOUT_FILENO.
152 Return true if successful. */
156 /* Pointer to the buffer, used by reads and writes. */
159 /* Number of characters preferably read or written by each read and write
163 /* Actual number of characters read, and therefore written. */
166 /* Loop until the end of the file. */
170 /* Read a block of input. */
172 n_read = safe_read (input_desc, buf, bufsize);
173 if (n_read == SAFE_READ_ERROR)
175 error (0, errno, "%s", infile);
179 /* End of this file? */
184 /* Write this block out. */
187 /* The following is ok, since we know that 0 < n_read. */
189 if (full_write (STDOUT_FILENO, buf, n) != n)
190 error (EXIT_FAILURE, errno, _("write error"));
195 /* Write any pending output to STDOUT_FILENO.
196 Pending is defined to be the *BPOUT - OUTBUF bytes starting at OUTBUF.
197 Then set *BPOUT to OUTPUT if it's not already that value. */
200 write_pending (char *outbuf, char **bpout)
202 size_t n_write = *bpout - outbuf;
205 if (full_write (STDOUT_FILENO, outbuf, n_write) != n_write)
206 error (EXIT_FAILURE, errno, _("write error"));
211 /* Cat the file behind INPUT_DESC to the file behind OUTPUT_DESC.
212 Return true if successful.
213 Called if any option more than -u was specified.
215 A newline character is always put at the end of the buffer, to make
216 an explicit test for buffer end unnecessary. */
220 /* Pointer to the beginning of the input buffer. */
223 /* Number of characters read in each read call. */
226 /* Pointer to the beginning of the output buffer. */
229 /* Number of characters written by each write call. */
232 /* Variables that have values according to the specified options. */
233 bool show_nonprinting,
236 bool number_nonblank,
240 /* Last character read from the input buffer. */
243 /* Pointer to the next character in the input buffer. */
246 /* Pointer to the first non-valid byte in the input buffer, i.e. the
247 current end of the buffer. */
250 /* Pointer to the position where the next character shall be written. */
253 /* Number of characters read by the last read call. */
256 /* Determines how many consecutive newlines there have been in the
257 input. 0 newlines makes NEWLINES -1, 1 newline makes NEWLINES 1,
258 etc. Initially 0 to indicate that we are at the beginning of a
259 new line. The "state" of the procedure is determined by
261 int newlines = newlines2;
264 /* If nonzero, use the FIONREAD ioctl, as an optimization.
265 (On Ultrix, it is not supported on NFS file systems.) */
266 bool use_fionread = true;
269 /* The inbuf pointers are initialized so that BPIN > EOB, and thereby input
270 is read immediately. */
281 /* Write if there are at least OUTSIZE bytes in OUTBUF. */
283 if (outbuf + outsize <= bpout)
286 size_t remaining_bytes;
289 if (full_write (STDOUT_FILENO, wp, outsize) != outsize)
290 error (EXIT_FAILURE, errno, _("write error"));
292 remaining_bytes = bpout - wp;
294 while (outsize <= remaining_bytes);
296 /* Move the remaining bytes to the beginning of the
299 memmove (outbuf, wp, remaining_bytes);
300 bpout = outbuf + remaining_bytes;
303 /* Is INBUF empty? */
307 bool input_pending = false;
311 /* Is there any input to read immediately?
312 If not, we are about to wait,
313 so write all buffered output before waiting. */
316 && ioctl (input_desc, FIONREAD, &n_to_read) < 0)
318 /* Ultrix returns EOPNOTSUPP on NFS;
319 HP-UX returns ENOTTY on pipes.
320 SunOS returns EINVAL and
321 More/BSD returns ENODEV on special files
323 Irix-5 returns ENOSYS on pipes. */
324 if (errno == EOPNOTSUPP || errno == ENOTTY
325 || errno == EINVAL || errno == ENODEV
327 use_fionread = false;
330 error (0, errno, _("cannot do ioctl on %s"), quote (infile));
331 newlines2 = newlines;
336 input_pending = true;
340 write_pending (outbuf, &bpout);
342 /* Read more input into INBUF. */
344 n_read = safe_read (input_desc, inbuf, insize);
345 if (n_read == SAFE_READ_ERROR)
347 error (0, errno, "%s", infile);
348 write_pending (outbuf, &bpout);
349 newlines2 = newlines;
354 write_pending (outbuf, &bpout);
355 newlines2 = newlines;
359 /* Update the pointers and insert a sentinel at the buffer
368 /* It was a real (not a sentinel) newline. */
370 /* Was the last line empty?
371 (i.e. have two or more consecutive newlines been read?) */
377 /* Limit this to 2 here. Otherwise, with lots of
378 consecutive newlines, the counter could wrap
379 around at INT_MAX. */
382 /* Are multiple adjacent empty lines to be substituted
383 by single ditto (-s), and this was the second empty
392 /* Are line numbers to be written at empty lines (-n)? */
394 if (number & !number_nonblank)
397 bpout = stpcpy (bpout, line_num_print);
401 /* Output a currency symbol if requested (-e). */
406 /* Output the newline. */
414 /* Are we at the beginning of a line, and line numbers are requested? */
416 if (newlines >= 0 && number)
419 bpout = stpcpy (bpout, line_num_print);
422 /* Here CH cannot contain a newline character. */
424 /* The loops below continue until a newline character is found,
425 which means that the buffer is empty or that a proper newline
428 /* If quoting, i.e. at least one of -v, -e, or -t specified,
429 scan for chars that need conversion. */
430 if (show_nonprinting)
460 *bpout++ = ch - 128 + 64;
464 else if (ch == '\t' && !show_tabs)
482 /* Not quoting, neither of -v, -e, or -t specified. */
485 if (ch == '\t' && show_tabs)
505 main (int argc, char **argv)
507 /* Optimal size of i/o operations of output. */
510 /* Optimal size of i/o operations of input. */
513 size_t page_size = getpagesize ();
515 /* Pointer to the input buffer. */
518 /* Pointer to the output buffer. */
524 /* Index in argv to processed argument. */
527 /* Device number of the output (file or whatever). */
530 /* I-node number of the output. */
533 /* True if the output file should not be the same as any input file. */
534 bool check_redirection = true;
536 /* Nonzero if we have ever read standard input. */
537 bool have_read_stdin = false;
539 struct stat stat_buf;
541 /* Variables that are set according to the specified options. */
543 bool number_nonblank = false;
544 bool squeeze_blank = false;
545 bool show_ends = false;
546 bool show_nonprinting = false;
547 bool show_tabs = false;
548 int file_open_mode = O_RDONLY;
550 static struct option const long_options[] =
552 {"number-nonblank", no_argument, NULL, 'b'},
553 {"number", no_argument, NULL, 'n'},
554 {"squeeze-blank", no_argument, NULL, 's'},
555 {"show-nonprinting", no_argument, NULL, 'v'},
556 {"show-ends", no_argument, NULL, 'E'},
557 {"show-tabs", no_argument, NULL, 'T'},
558 {"show-all", no_argument, NULL, 'A'},
559 {GETOPT_HELP_OPTION_DECL},
560 {GETOPT_VERSION_OPTION_DECL},
564 initialize_main (&argc, &argv);
565 set_program_name (argv[0]);
566 setlocale (LC_ALL, "");
567 bindtextdomain (PACKAGE, LOCALEDIR);
568 textdomain (PACKAGE);
570 /* Arrange to close stdout if we exit via the
571 case_GETOPT_HELP_CHAR or case_GETOPT_VERSION_CHAR code.
572 Normally STDOUT_FILENO is used rather than stdout, so
573 close_stdout does nothing. */
574 atexit (close_stdout);
576 /* Parse command line options. */
578 while ((c = getopt_long (argc, argv, "benstuvAET", long_options, NULL))
585 number_nonblank = true;
590 show_nonprinting = true;
598 squeeze_blank = true;
603 show_nonprinting = true;
607 /* We provide the -u feature unconditionally. */
611 show_nonprinting = true;
615 show_nonprinting = true;
628 case_GETOPT_HELP_CHAR;
630 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
633 usage (EXIT_FAILURE);
637 /* Get device, i-node number, and optimal blocksize of output. */
639 if (fstat (STDOUT_FILENO, &stat_buf) < 0)
640 error (EXIT_FAILURE, errno, _("standard output"));
642 outsize = ST_BLKSIZE (stat_buf);
643 /* Input file can be output file for non-regular files.
644 fstat on pipes returns S_IFSOCK on some systems, S_IFIFO
645 on others, so the checking should not be done for those types,
646 and to allow things like cat < /dev/tty > /dev/tty, checking
647 is not done for device files either. */
649 if (S_ISREG (stat_buf.st_mode))
651 out_dev = stat_buf.st_dev;
652 out_ino = stat_buf.st_ino;
656 check_redirection = false;
657 #ifdef lint /* Suppress `used before initialized' warning. */
663 if (! (number | show_ends | squeeze_blank))
665 file_open_mode |= O_BINARY;
666 if (O_BINARY && ! isatty (STDOUT_FILENO))
667 freopen (NULL, "wb", stdout);
670 /* Check if any of the input files are the same as the output file. */
680 infile = argv[argind];
682 if (STREQ (infile, "-"))
684 have_read_stdin = true;
685 input_desc = STDIN_FILENO;
686 if ((file_open_mode & O_BINARY) && ! isatty (STDIN_FILENO))
687 freopen (NULL, "rb", stdin);
691 input_desc = open (infile, file_open_mode);
694 error (0, errno, "%s", infile);
700 if (fstat (input_desc, &stat_buf) < 0)
702 error (0, errno, "%s", infile);
706 insize = ST_BLKSIZE (stat_buf);
708 /* Compare the device and i-node numbers of this input file with
709 the corresponding values of the (output file associated with)
710 stdout, and skip this input file if they coincide. Input
711 files cannot be redirected to themselves. */
713 if (check_redirection
714 && stat_buf.st_dev == out_dev && stat_buf.st_ino == out_ino
715 && (input_desc != STDIN_FILENO))
717 error (0, 0, _("%s: input file is output file"), infile);
722 /* Select which version of `cat' to use. If any format-oriented
723 options were given use `cat'; otherwise use `simple_cat'. */
725 if (! (number | show_ends | show_nonprinting
726 | show_tabs | squeeze_blank))
728 insize = max (insize, outsize);
729 inbuf = xmalloc (insize + page_size - 1);
731 ok &= simple_cat (ptr_align (inbuf, page_size), insize);
735 inbuf = xmalloc (insize + 1 + page_size - 1);
738 (OUTSIZE - 1 + INSIZE * 4 + LINE_COUNTER_BUF_LEN + PAGE_SIZE - 1)
739 bytes allocated for the output buffer?
741 A test whether output needs to be written is done when the input
742 buffer empties or when a newline appears in the input. After
743 output is written, at most (OUTSIZE - 1) bytes will remain in the
744 buffer. Now INSIZE bytes of input is read. Each input character
745 may grow by a factor of 4 (by the prepending of M-^). If all
746 characters do, and no newlines appear in this block of input, we
747 will have at most (OUTSIZE - 1 + INSIZE * 4) bytes in the buffer.
748 If the last character in the preceding block of input was a
749 newline, a line number may be written (according to the given
750 options) as the first thing in the output buffer. (Done after the
751 new input is read, but before processing of the input begins.)
752 A line number requires seldom more than LINE_COUNTER_BUF_LEN
755 Align the output buffer to a page size boundary, for efficency on
756 some paging implementations, so add PAGE_SIZE - 1 bytes to the
757 request to make room for the alignment. */
759 outbuf = xmalloc (outsize - 1 + insize * 4 + LINE_COUNTER_BUF_LEN
762 ok &= cat (ptr_align (inbuf, page_size), insize,
763 ptr_align (outbuf, page_size), outsize, show_nonprinting,
764 show_tabs, number, number_nonblank, show_ends,
773 if (!STREQ (infile, "-") && close (input_desc) < 0)
775 error (0, errno, "%s", infile);
779 while (++argind < argc);
781 if (have_read_stdin && close (STDIN_FILENO) < 0)
782 error (EXIT_FAILURE, errno, _("closing standard input"));
784 exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);